What are the minor heart sounds S3 and S4?

What are the minor heart sounds S3 and S4?

• A. S1 and S2
• B. S3 and S4 are minor heart sounds
• C. S5 and S6
• D. S7 and S8

Answer: (B)

Understanding heart sounds involves separating the normal two sounds from the extra ones that can appear. The two primary sounds come from the closures of the valves at the start and end of each heartbeat. The minor heart sounds are S3 and S4. S3 occurs just after the second heart sound in early diastole when the ventricle is rapidly filling; it can be normal in children and young adults but may indicate volume overload or systolic dysfunction in older adults. S4 happens late in diastole, just before the first heart sound, when the atria contract to push blood into a stiff or noncompliant ventricle; this is often associated with ventricular hypertrophy or long-standing hypertension. These two are considered the additional or minor sounds, distinct from the primary S1 and S2. The other sounds (not part of the standard minor set) are not typically described as common minor heart sounds.

Understanding heart sounds involves separating the normal two sounds from the extra ones that can appear. The two primary sounds come from the closures of the valves at the start and end of each heartbeat. The minor heart sounds are S3 and S4. S3 occurs just after the second heart sound in early diastole when the ventricle is rapidly filling; it can be normal in children and young adults but may indicate volume overload or systolic dysfunction in older adults. S4 happens late in diastole, just before the first heart sound, when the atria contract to push blood into a stiff or noncompliant ventricle; this is often associated with ventricular hypertrophy or long-standing hypertension. These two are considered the additional or minor sounds, distinct from the primary S1 and S2. The other sounds (not part of the standard minor set) are not typically described as common minor heart sounds.